This is a question of finding the time to update the toolchain on buildbot. Buildbot runs on Debian and we need a cross compilation toolchain. However the toolchain I use to make the official 64 bits macOS releases is a native macOS toolchain and is not directly transferable. Also I have no experience of cross compilation, which makes this task a bit more daunting for me.

I would be possible to compile a fat binary in theory, but my plan is rather to have two separate binaries that target different OS version (a 64 bits binary for macOS 10.7 or above, and a 32 bits one that can be used on older versions).

Thanks, I was not meaning to apply any pressure if it's not a straight forward process. The service is appreciated and I hope that there will be a solution in the future when you can find the time to investigate it further.